Retrofit Roof System and a Clip Therefor

ABSTRACT

A roofing system for retrofitting an installed roof with a new roof and a coupling member, or clip, therefor. In some embodiments, the clip includes a housing adapted for slideable engagement with a subframe coupled to an installed roof panel and a rail adapted to couple with a new roof panel. The housing has a slot extending therethrough. The rail extends through the slot and is slideable relative to the housing within the slot.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application Serial No. 61/173,848 filed on Apr. 29, 2009, and entitled “Retrofit Roof System and a Clip Therefor,” which is hereby incorporated herein by reference in its entirety for all purposes

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

The present invention relates generally to a system for retrofitting a roof envelope of a building. More particularly, the present invention relates to a system for installing a new roof, formed of new roof decking panels, over an existing roof. Still more particularly, the present invention relates to a clip that enables coupling of a roof subframe system to a span of the new roof decking panels.

Metal roof decking is a building envelope system made from metal decking panels. One common type of metal roof decking is known as a fluted, or ribbed, roof decking. Ribbed metal roof decking includes a plurality of ribbed metal roof decking panels, each panel characterized by a sequence of alternating upper and lower surfaces that extend the length of the panel. The upper surfaces, or ribs, are found substantially in an upper plane, and are substantially parallel to each other. Likewise, the lower surfaces, or valleys, are found substantially in a lower plane, one that is generally parallel to and spaced vertically apart from the upper plane. The upper and lower surfaces are connected by a series of vertical or sloped walls which also extend the length of the panel. The upper, lower and vertical or sloped walls define flutes, or channels.

When installed to form metal roof decking, the ribbed metal roof decking panels typically overlap one another to form a continuous span. The metal roof decking panels are secured by fasteners to underlying support structures, sometimes referred to as purlins. The metal roof decking panels may also be secured to one another by forming a standing seam at adjacent edges of the roof decking panels.

For various reasons, the metal roof decking of a building, in part or whole, may be in need of repair, replacement, upgrade, or a general retrofit. Due to the lightweight qualities of some metal roof decking, an existing roof may be retrofit by installing a system of subframes over the existing roof decking, and then securing new roof decking to the subframe system. The use of subframe systems in this manner provides additional support and points of attachment for the new roof decking.

In many conventional retrofit roof systems, the new roof system is coupled to the subframe system at discrete locations. For example, the new roof system may include fastener panels coupled by a plurality of fasteners to the subframe system. As another example, the new roof system may include standing seam panels coupled by a combination of fasteners and clips to the roof subframe system. Uplift loads, such as those induced by wind, to the new roof system are resisted by these coupling devices. Thus, the combined cross-section of the coupling devices limits the capacity of the roofing system to withstand uplift loads. Coupling devices located in corner and/or edge zones of the roof envelope may not provide adequate resistance to the uplift loads. This may be because the coupling devices were improperly installed, that there are an insufficient number of them to resist the uplift loads, or a combination of both. Consequently, the coupling devices may fail, allowing a portion of the new roof system to become unattached to the subframe system or removed entirely.

Accordingly, there remains a need for an improved roof system for use in the retrofit of existing roof systems that address certain of the foregoing difficulties. It would be particularly desirable if the roof system enables increased ability of the roof envelope to resist uplift loads and increased thermal efficiency of sheathing ventilation of a building on which the roof system is installed.

SUMMARY OF THE DISCLOSED EMBODIMENTS

Certain of the shortcomings noted above are addressed, at least in part, by a roofing system for retrofitting an existing, or already installed, roof with a new roof and having a coupling member, or clip. In some embodiments, the clip includes a housing adapted for slideable engagement with a subframe coupled to an installed roof panel and a rail adapted to couple with a new roof panel. The housing has a slot extending therethrough. The rail extends through the slot and is slideable relative to the housing within the slot.

In some embodiments, the roof system includes a roof panel installed on a building, a subframe coupled to the roof panel, and the coupling member slideably interlocked with the subframe. Further, in some embodiments, the roof system includes a subframe, the coupling member slideably interlocked with the subframe, and a roof panel supported by the coupling member.

Thus, the embodiments disclosed herein comprise a combination of features and characteristics that are directed to overcoming various shortcomings of prior roofing systems. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the preferred embodiment of the present invention, reference will be made to the accompanying drawings, wherein:

FIGS. 1A and 1B are schematic side and end views, respectively, of an embodiment of a retrofit roof system in accordance with the principles disclosed herein;

FIG. 2 is a perspective view of the existing roof system of FIGS. 1A and 1B;

FIG. 3 is a perspective view of a roof subframe of the roof subframe system of FIGS. 1A and 1B;

FIG. 4 is a perspective view of the roof subframe system of FIG. 3 installed over the existing roof system of FIG. 2;

FIGS. 5A through 5C are side, end, and top views, respectively, of the clip base of FIGS. 1A and 1B;

FIGS. 6A through 6C are side, end, side, and top views, respectively, of the clip rail of FIGS. 1A and 1B;

FIGS. 7A through 7C are side, end, and top views, respectively, of the clip of FIGS. 1A and 1B;

FIG. 8 is a perspective view of one support bridging panel of FIGS. 1A and 1B; and

FIG. 9 is a perspective view of one new roof deck panel of the new roofing system of FIGS. 1A and 1B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is directed to exemplary embodiments of a retrofit roof system. The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. One skilled in the art will understand that the following description has broad application, and that the discussion is meant only to be exemplary of the described embodiments, and not intended to suggest that the scope of the disclosure, including the claims, is limited only to those embodiments.

Certain terms are used throughout the following description and the claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features and components described herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness.

In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to. . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, the connection between the first device and the second device may be through a direct connection, or through an indirect connection via other intermediate devices and connections.

Referring now to FIGS. 1A and 1B, schematic side and end views, respectively, of an embodiment of a retrofit roof system are shown. Retrofit roof system 100 includes a roof subframe system 105 coupled between an existing roof system 110 and a new roof system 115. Roof subframe system 105 is coupled to existing roof system 110 by a plurality of fasteners 155, and to new roof system 115 by a plurality of coupling members, or clips, 125. Clips 125 support new roof system 115 such that a clearance or gap 160 is formed between roof subframe system 105 and new roof system 115. In some embodiments, retrofit roof system 100 also includes a plurality of support bridging panels 170 disposed within gap 160 between roof subframe system 105 and new roof system 115, and/or a layer of insulation 175 disposed over existing roof system 110. Support bridging panels 170 are supported by roof subframe system 105.

Existing roof system 110 includes a plurality of purlin supports 140 supporting a plurality of overlapping, existing roof deck panels 145. Referring to FIG. 2, each purlin support 140 has a top flange 165 configured to support an existing roof deck panel 145 and to receive one or more fasteners 155 (FIG. 1B) that couple roof subframe system 105 and the existing roof deck panel 145. Existing roof deck panel 145 includes a plurality of ribs 190, each rib 190 positioned between and extending from two adjacent valleys 195. In some embodiments, each of flange 165 of purlin support 140 and existing roof deck panel 145 includes one or more throughbores 265 that, when aligned, enable coupling of purlin support 140 and existing roof deck panel 145 via fasteners 155, as will be described.

Roof subframe system 105 includes a plurality of subframes 150. Referring to FIG. 3, each subframe 150 is an elongate support member that may be manufactured from a variety of metals having a wide range of thicknesses, including but not limited to, 14 or 16 gauge steel. In end view or in cross-section, subframe 150 may be described as generally hat-shaped. The “hat shape” of subframe 150 refers to the shape of its cross-section, which, when inverted from its orientation shown in FIG. 3, appears like a hat with a brim.

Subframe 150 includes a base portion 205 that is spaced apart from two opposing surfaces, first longitudinal flange 210 and second longitudinal flange 215. First and second longitudinal flanges 210, 215 are generally coplanar and oriented in a generally horizontal plane that is parallel to a plane including base 205. Further, flanges 210, 215 are substantially symmetric about the longitudinal axis 220 of subframe 150. A first lip 235 extends from a first edge of first longitudinal flange 210 at an angle 217 extending between interior surfaces of first longitudinal flange 210 and first lip 235, as shown. Similarly, a second lip 240 extends from a first edge of second longitudinal flange 215 at an angle 219 extending between interior surfaces of second longitudinal flange 215 and second lip 240, as also shown. In some embodiments, including those illustrated by FIG. 3, angles 217, 219 are each approximately 135 degrees. However, in other embodiments, angles 217, 219 may be less than or greater than 135 degrees.

A first wall 225 and a second wall 230 extend vertically downward from a second edge of first longitudinal flange 210 and a second edge of second longitudinal flange 215, respectively. First and second walls 225, 230 are normal to first and second longitudinal flanges 210, 215 in this embodiment. However, in other embodiments, first and second walls 225, 230 may extend from first and second longitudinal flanges 210, 215 in other angular orientations. First and second walls 225, 230 are coupled to and interconnected by base 205. As shown, base 205 is the lowermost portion of subframe 150 and extends horizontally between respective ends of first and second walls 225, 230. In some embodiments, base 205 includes one or more throughbores 250 that enable coupling of subframe 150 to existing roof system 110, as will be described. A channel 245 is formed by first wall 225, base 205, and second wall 230.

A void, or punch out, 255 is created in subframe 150. Punch out 255 extends along a central axis 260 that is generally perpendicular to the longitudinal axis 220 of subframe 150. Punch out 255 passes through corresponding sections of first wall 225, second wall 230, and base 205. Punch out 255 is configured to matingly receive, or fit over, a rib 190 of the existing roof deck panel 145 when subframe 150 is installed over the existing roof deck panel 145, as illustrated in FIG. 4.

Referring still to FIG. 3, punch out 255 has a generally trapezoidal shape when viewed in a direction parallel to central axis 260. Punch out 255 may have other shapes, however. The trapezoidal shape is one selected to generally correspond to or match the shape of raised ribs on many conventional metal roof panels. While subframe 150 is depicted as having a single punch out 255, subframe 150 typically will include a plurality of punch outs 255 positioned at intervals along the length of subframe 150, thereby allowing subframe 150 to mate with a number of raised ribs 190 of the existing roof deck panel 145.

To couple roof subframe system 105 to existing roof system 110, as shown in FIG. 4, each subframe 150 is positioned over an existing roof deck panel 145 in alignment with a purlin support 140 such that longitudinal flanges 210, 215 of subframe 150 extend generally perpendicular to ribs 190 of existing roof deck panel 145. When aligned with purlin support 140, base 205 of subframe 150 rests on valleys 195 of existing roof deck panel 145 with punch out 255 of subframe 150 positioned over a rib 190 of existing roof deck panel 145. Further, throughbores 250 in base 205 of subframe 150 are aligned with throughbores 265 of existing deck panel 145 and purlin support 140. Fasteners 155 are then inserted through base 205 of subframe 150, valley 195 of existing roof deck panel 145, and flange 165 of purlin support 140 at intervals along the length of subframe 150 to couple subframe 150 and existing roof deck panel 145 to purlin support 140. In some embodiments, each fastener 155 is a self-tapping fastener.

Each clip 125 includes a base 130 and a rail 135 coupled thereto. Referring to FIGS. 5A through 5C, side, end, and top views of base 130 of clip 125 are shown. Base 130 is a substantially rectangular structure, or housing, having two opposing sides 270, two opposing ends 275, a top 280, and a bottom 345. As best viewed in FIG. 5C, top 280 includes a slot 285 extending therethrough and substantially normally between sides 270. Slot 285 has a width 290 configured to enable rail 135 to extend therethrough, as will be described. As best viewed in FIG. 5A, each side 270 includes a punch out 295 connected to an end of slot 285 and configured to enable rail 135 to be inserted therethrough. In some embodiments, the shape of punch out 295 is substantially similar to a cross-section of rail 135.

In the illustrated embodiment shown in FIGS. 5A-5C, punch out 295 has an inverted T shape, the base of which is connected to an end of slot 285. Punch out 295 includes a vertically extending portion 300 connected to and extending from slot 285, and laterally extending portion 305 connected thereto. At the ends of lateral portion 305, punch out 295 further includes two end portions 310. Each end portion 310 is angled relative to lateral portion 305 by an angle 312. In this embodiment, end portions 310 extend downward, or away from top 280 of base 130, and are oriented substantially normally to lateral portion 305, meaning angle 312 is approximately 90 degrees. However, in other embodiments, end portions 310 may extend in the opposite direction, or upward. Furthermore, end portions 310 may not be normal to lateral portion 305, but rather oriented relative to lateral portion 305 such that angle 312 is less than or greater than 90 degrees.

As best viewed in FIG. 5B, each side 270 extends downwardly from top 280. Each side 270 includes a vertical portion 315 coupled along an edge to top 285 and an angled portion 320 coupled along an edge to vertical portion 315. The angled orientation of portion 320, relative to vertical portion 315, is characterized by an angle 325 extending between interior surfaces 330, 335 of portions 315, 320, respectively. Angle 325 is preferably less than 90 degrees, or acute, to enable interlocking of subframe 150 and base 130, as will be described.

Each end 275 also extends downwardly from top 285. Each end 275 includes a vertical portion 340 coupled between edges of top 280 and bottom 345. A flanged portion 350 extends downwardly from bottom 345 and substantially parallel to sides 270 of base 130. Flanged portion 350 has a width 355 configured to enable insertion of flanged portion 350 within channel 245 of subframe 150 when clip 125 is coupled to roof subframe system 105, as will be described.

Surfaces 335, 330 of sides 270 and bottom 345, including flanged portion 350, bound an interior region 360 of base 130. As illustrated by FIG. 1B, subframe 150 of roof subframe system 105 is insertable within, or slideable into, interior region 360 of base 130 such that flanged portion 350 of base 130 is received within channel 245 of subframe 150, bottom 345 of base 130 is supported by first and second longitudinal flanges 210, 215 of subframe 150, and lips 235, 240 extending from first and second longitudinal flanges 210, 215 are each disposed between bottom 345 of base 130, vertical portion 315 of opposing sides 270 of base 130, and angled portion 320 of opposing sides 270 of base 130. When subframe 150 is inserted within base 130, as described and shown, subframe 150 is slideable relative to base 130 in a direction substantially parallel to a longitudinal axis of subframe 150. At the same time, movement of subframe 150 relative to base 130 in any other direction is limited by clearance between subframe 150 and bottom 345, vertical portion 315, and angled portion 320 of base 130. Thus, subframe 150 may be described as being slideably interlocked with base 130, or vice versa.

Turning now to FIGS. 6A through 6C, side, end, and top views, respectively, of rail 135 of clip 125 are shown. Rail 135 is an elongate member having a length 365 and a cross-section 370. Rail 135 further includes a vertically extending portion 375 coupled between two laterally extending portions 380, 385, an end portion 387 extending downwardly from lateral portion 380 along its edge distal to vertical portion 375, and two end portions 400 coupled to opposing ends of lateral portion 380. End portions 400 are oriented relative to lateral portion 385 in a manner similar to the orientation of end portions 310 relative to lateral portion 305 of base 130. In this embodiment, end portions 310 of base 130 extend downward from and normal to lateral portion 305. Thus, in this embodiment, end portions 400 also extend downward from and normal to lateral portion 385 of rail 135.

Lateral portion 380 has an interior width 390 and an exterior width 392. End portion 387 has a height 395. An interior region 430 is formed between end portion 387, lateral portion 380, and the upper end of vertical portion 375. Vertical portion 375 has an interior height 377.

Cross-section 370 of rail 135 is configured to enable rail 135 to be received through punch outs 295 of base 130 of clip 125 and extend through slot 285 of base 130, as shown in FIGS. 7A through 7C. In this embodiment, cross-section 370 of rail 135 has an inverted T-shape, similar to the inverted T-shape of punch outs 295 of base 130. Further, vertical portion 375 has a width and length which enable vertical portion 375 to be inserted through vertical portions 300 of punch outs 295 of base 130 such that lateral portion 380 and end portion 387 extending therefrom are outside of base 130, as best viewed in FIG. 7A. The lengths and widths of lateral portion 385 and end portions 400 are such that lateral portion 385 extends through lateral portions 305 of punch outs 295 and end portions 400 extend through end portions 310 of punch outs 295.

When rail 135 is inserted through punch outs 295 and slot 285 of base 130, as illustrated by FIGS. 7A through 7C, rail 135 may move, or slide, relative to base 130 in a direction parallel to slot 285. At the same time, movement of rail 135 relative to base 130 in a different direction is limited by clearances between rail 135 and the edges of base 130 that define slot 285 and punch outs 295. Thus, rail 135 may be described as being slideably interlocked with base 130, or vice versa.

Length 365 of rail 135 is selected to enable continuous coupling of clip 125 to new roof system 115, as will be described. In some embodiments, length 365 is selected to enable rail 135 to extend between two adjacent clips 125 spaced some distance apart, as illustrated by FIGS. 7B and 7C. In other embodiments, length 365 is selected to enable rail 135 to extend through two or more clips 125.

Referring next to FIG. 8, each support bridging panel 170 includes a plurality of ribs 405, each rib 405 positioned between and extending from two adjacent valleys 410. Each panel 170 has a width 415, and each rib 405 of panel 170 has a height 420. Panel width 415 is selected to enable positioning of panel 170 on roof subframe system 105 between adjacent clips 125, as shown in FIG. 1A. Moreover, height 420 of ribs 405 are selected to enable positioning of panel 170 within gap 160 between roof subframe system 105 and new roof system 115.

New roof system 115 includes a plurality of overlapping, new roof deck panels 425. Turning finally to FIG. 9, each new roof deck panel 425 has a base portion 435 extending between end portions 440, 445. Base portion 435 is substantially flat. However, in some embodiments, base portion 435 may include one or more stiffening ribs, each rib extending along base portion 435 in a direction substantially parallel to the longitudinal axis 455 of new roof deck panel 425. Moreover, edges of base portion 435 proximate end portions 440, 445 each may raised to accommodate for positioning of new roof deck panel 425 between and over adjacent clips 125, as shown in FIG. 1A.

Still referring to FIG. 9, edge portions 440, 445 of new roof deck panel 425 enable coupling of new roof deck panel 425 between the rails 135 of two adjacent clips 125. Edge portion 440 is configured to be received within interior region 430 (FIG. 6A) of a rail 135 of one clip 125 with base portion 435 of new roof deck panel 425 supported by the base 130 of the clip 125. Edge portion 445 of new roof deck panel 425 forms an interior region 450. Edge portion 445 is configured to be positioned over the rail 135 of an adjacent clip 125, such that the rail 135 is received with interior region 450 of edge portion 445.

In the illustrated embodiment of new roof deck panel 425, edge portion 440 has a vertical portion 460 extending upward from base portion 435, and a lip 465 extending laterally therefrom. Lip 465 has a width 470, and vertical portion 460 has a height 462. Edge portion 445 has a vertical portion 475 extending upward from base 435, a lateral portion 480 extending therefrom, and a lip 485 extending downward from lateral portion 480 along its edge distal vertical portion 475. Lip 485, lateral portion 480, and the upper end of vertical portion 475 bound interior region 450. Lip 485 has a height 490, and lateral portion 480 has a width 495.

Each rail 135 is configured such that interior width 390 (FIG. 6A) of lateral portion 380 of rail 135 is greater than width 470 of lip 465 of new roof deck panel 425, and interior height 377 (FIG. 6A) of vertical portion 375 of rail 135 is greater than height 462 of vertical portion 460 of new roof deck panel 425. Thus, interior region 430 of rail 135 may receive an edge portion 440 of a new roof deck panel 425 therein. Each rail 135 is further configured such that exterior width 392 (FIG. 6A) of lateral portion 380 of rail 135 is less than width 495 of lateral portion 480 of new roof deck panel 425, and height 395 (FIG. 6A) of edge portion 387 of rail 135 is substantially the same as height 490 of lip 485 of new roof deck panel 425. As such, rail 135 is also configured to be received within an interior region 450 of an edge portion 445 of an adjacent new deck panel 425.

Once so positioned, as illustrated in FIG. 1A, edge portions 440, 445 of new roof deck panels 125 with rail 135 disposed therebetween are further coupled by folding lip 485 of edge portion 445 and edge portion 387 of rail 135 under lip 465 of edge portion 440, lateral portion 380 of rail 135, and lateral portion 480 of edge portion 445. To promote this coupling, lateral portion 480 of edge portion 445 of new roof deck panel 425, lateral portion 380 of rail 135, and lip 465 of edge portion 440 of new roof deck panel 425 may then be folded toward vertical portion 475 of edge portion 445, vertical portion 375 of rail 135, and vertical portion 460 of edge portion 440.

Thus, in accordance with the principles disclosed herein, rails 135 of clips 125 are configured to enable edge portions 440, 445 of adjacent new roof panel deck panels 425 to be inserted within and over, respectively, rails 135, as illustrated by FIG. 1A. In this manner, edge portions 440, 445 of adjacent new roof deck panels 425 are interlocked with each other and with a rail 135 disposed therebetween. Edge portions 440, 445 with rail 135 disposed therebetween are subsequently folded over at least once to further couple the adjacent new roof deck panels 425 to rail 135. This enables a continuous coupling of new roof system 115 to clips 125, and therefore roof subframe system 105 and existing roof system 110. Further, this coupling provides a continuous seal through which moisture, such as rain or melted snow, may not pass.

The embodiment of new roof deck panel 425 described and illustrated with reference to FIG. 9 is a design common to the roofing industry. Even so, retrofit roof systems in accordance with the principles disclosed herein are not limited to this particular embodiment of new roof deck panel 425. Rather, new roof deck panel 425, and in particular, its edge portions 440, 445, may take other design configurations. In such embodiments, the dimensioning and cross-sectional shape of rail 135 is selected to enable the modified edge portions 440, 445 of adjacent new roof deck panels 425 to be interlocked with rails 135 and coupled thereto in a manner substantially similar to that described above.

Returning to FIGS. 1A and 1B, retrofit roof systems in accordance with the principles disclosed herein, including retrofit roof system 100, have a variety of structural features that enable increased structural capacity, wind load resistance, and thermal efficiency over that offered by conventional roofing systems. For instance, coupling of new roof system 115 to roof subframe system 105 and existing roof system 110 via clips 125 enables limited displacement or movement of new roof system 115 relative to roof subframe system 105 and existing roof system 110. As described above, new roof deck panels 425 of new roof system 105 are coupled to clips 125 via rails 135. Clips 125 are coupled to roof subframe system 105 via bases 130. Each rail 135 extends through one or more bases 130 via punch outs 295, but is not fastened to base 130. As such, rail 135 may translate, or slide, relative to base 130 in a direction parallel to slot 285 of base 130. Moreover, subframe 150 of roof subframe system 150 also extends through base 130, but is not fastened to base 130. Thus, base 130 may translate, or slide, relative to subframe 150 in a direction parallel to the longitudinal axis 220 of subframe 150.

Consequently, when new roof system 115 displaces, for example, due to thermal expansion or contraction of new roof deck panels 425 in response to changing ambient temperature and/or radiant loads, new roof system 115 is permitted limited displacement relative to subframe system 105 and existing roof system 110, while remaining coupled thereto. Enabling limited displacement of new roof system 115 in this manner reduces stresses levels to new roof system 115, roof subframe system 105, and the coupling between the two, namely clips 125. Reduced stresses, in turn, enable reduced fatigue damage to and longer service life of the affected components.

In many conventional retrofit roof systems, the new roof system is coupled to the roof subframe system at discrete locations, for example, by a plurality of clips and/or fasteners. Uplift loads to the new roof system are resisted by these clips and fasteners. Thus, the combined cross-section of the clips and fasteners limits the capacity of the roofing system to withstand uplift loads.

In contrast, uplift loads to new roof system 115 of retrofit roof system 100 are resisted by clips 125, which provide a significantly broader cross-section than that of conventional fasteners. First, the coupling between new roof system 115 and rails 135 of clips 125 is continuous across the span of roofing system 100, rather than discrete. Second, when rails 135 are pulled vertically relative to bases 130, loads to rails 135 are resisted by bases 130 over the engagement area between lateral portions 380 of rails 135 and tops 280 of bases 130. Third, roof subframe system 105 resists load from bases 130 over the continuous engagement area between lips 235, 240 of subframes 150 and angled portions 320 and vertical portions 315 of bases 130. Thus, the cross-section of the coupling between new roof system 115 and roof subframe system 105 is significantly broader than that of conventional roofing systems. Hence, uplift loads are distributed across greater area, thereby enabling clips 125, and therefore retrofit roof system 100, to withstand higher uplift loads, as compared to their conventional counterparts.

Additionally, coupling new roof system 115 to roof subframe system 105 via clips 125 provides gap 160 therebetween. The width of gap 160 is controlled by the dimensioning of clips 125, in particular bases 130 of clips 125. Preferably, bases 130 of clips 125 are sized such that gap 160 is up to four inches in width. In some embodiments, however, gap 160 may be in excess of four inches deep.

Retrofit roof system 100 enables air to pass through gap 160 between new roof system 115 and existing roof system 110. In hot environments, such air flow enables removal of a portion of the heat transferred from the surrounding environment through new roof system 115, thereby eliminating the transfer of that heat through existing roof system 110 into the interior of a building coupled thereto. This enables the building interior to remain cooler. In cold environments, the opposite is true. Thus, gap 160 enables improved thermal efficiency of the building upon which retrofit roof system 100 is installed.

In embodiments of retrofit roof system 100 having support bridging panels 170, such panels 170 provide structural support to new roofing system 115. This enables new roofing system 115 to resist loads and prevent accompanying damage from, for example, snow, ice, fallen tree branches, and human traffic during installation. Further, panels 170 restrain insulation 175, if present, and prevent insulation 175 from expanding into gap 160, where insulation 175 may impede air flow.

While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching herein. The embodiments described herein are exemplary only and are not limiting. It will be appreciated that many other modifications and improvements to the disclosed embodiments may be made without departing from the inventive concepts herein disclosed. Because many varying and different embodiments may be made within the scope of the present inventive concept, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. 

1. A clip for coupling a new roof panel to an installed roof panel, the clip comprising: a housing adapted for slideable engagement with a subframe coupled to the installed roof panel, the housing having slot extending therethrough; and a rail extending through the slot of the housing and adapted to couple with the new roof panel; wherein the rail is slideable relative to the housing.
 2. The clip of claim 1, wherein the housing further comprises a top having the slot extending therethrough and two opposing ends, each end extending from the top and having a punch out extending therethrough, and wherein the rail extends through both of the punch outs.
 3. The clip of claim 2, wherein the housing further comprises a bottom extending substantially parallel to the top and spatially offset therefrom, the bottom having a flange extending therefrom and configured to be slideably received within the subframe.
 4. The clip of claim 1, wherein the housing further comprises a top and two opposing sides, each side extending from the top and having a first portion substantially normal to the top and a second portion extending at an acute angle from the first portion toward the top.
 5. The clip of claim 1, wherein the slot is disposed in a top of the housing and wherein the rail comprises a first portion and a second portion connected to the first portion, wherein first portion has a width measured in a direction parallel to the top exceeding a width of the slot and the second portion extends through the slot.
 6. The clip of claim 5, wherein the rail further comprises a flanged portion extending normally from the second portion, the flanged portion configured to couple with the new roof panel.
 7. A roof system comprising: a roof panel installed on a building; a subframe coupled to the roof panel; and a coupling member slideably interlocked with the subframe.
 8. The roof system of claim 7, wherein the coupling member comprises a housing moveable relative the subframe in a direction substantially parallel to a longitudinal axis of the housing.
 9. The roof system of claim 8, wherein the housing comprises two opposing sides, each side having an angled portion, and wherein the subframe is disposed between each angled portion and a bottom of the housing, whereby the coupling member and the subframe are interlocked.
 10. The roof system of claim 8, wherein the housing comprises two opposing ends, each end having a punch out extending therethrough.
 11. The roof system of claim 10, wherein the coupling member further comprises a rail extending through both punch outs and slideable relative to the housing.
 12. The roof system of claim 11, wherein the housing further comprises a top extending between the two ends and having a slot extending therethrough, the slot connected to both of the punch outs and wherein the rail extends through the slot.
 13. A roof system comprising: a subframe; a coupling member slideably interlocked with the subframe; and a roof panel supported by the coupling member.
 14. The roof system of claim 13, wherein the coupling member comprises a rail having a flanged portion coupled to the roof panel.
 15. The roof system of claim 14, wherein the coupling member further comprises a housing having a top with a slot extending therethrough and wherein the rail extends through the slot and is moveable relative to the housing.
 16. The roof system of claim 13, wherein the coupling member comprises a housing moveable relative the subframe in a direction substantially parallel to a longitudinal axis of the subframe.
 17. The roof system of claim 16, wherein the housing comprises two opposing sides, each side having an angled portion, and wherein the subframe is inserted between each angled portion and a bottom of the housing, whereby the coupling member and the subframe are interlocked.
 18. The roof system of claim 16, wherein the housing comprises two opposing ends, each end having a punch out extending therethrough.
 19. The roof system of claim 18, wherein the coupling member further comprises a rail extending through both punch outs and slideable relative to the housing.
 20. The roof system of claim 13, wherein the coupling member comprises a housing slideably interlocked with the subframe and a rail slideably interlocked with the housing.
 21. The roof system of claim 20, further comprising a second roof panel coupled to the subframe.
 22. The roof system of claim 21, further comprising a gap disposed between the roof panels.
 23. The roof system of claim 22, further comprising a support panel disposed in the gap and supported by the subframe.
 24. The roof system of claim 22, further comprising insulation disposed in the gap. 